Razor with movable guard and concurrently movable blade platform

ABSTRACT

A safety razor having a head portion including blade positioning structure arranged to permit the blade cutting edge to move relative to the head portion and including biasing means for urging the blade towards a first position of normal exposure and a guard member mounted for movement between first and second positions. The guard member is disposed to engage the blade positioning structure so that movement of the guard member causes movement of the blade cutting edge.

United States Patent Nissen et a].

RAZOR WITH MOVABLE GUARD AND CONCURRENTLY MOVABLE BLADE PLATFORM lnventors: Warren 1. Nissen, Topsfield; Roger L. Perry, Lynnfield, both of Mass.

The Gillette Company, Boston, Mass.

Filed: Apr. 30, 1973 Appl. No.: 355,307

Assignee:

U.S. Cl. 30/63, 30/77 Int. Cl. B26b 21/24 Field of Search 30/40.2, 62, 63, 64, 75,

References Cited UNITED STATES PATENTS Kondolf 30/77 X Peck 30/77 X Mar. 18, 1975 3,253,335 5/1966 Kruger 30/62 3,657,810 4/1972 Nissen .f. 30/63 3,657,811 4/1972 Nissen et a1. 30/77 3,740,841 6/1973 Risher 30/77 X Primary E.\'aminerA1 Lawrence Smith Assistant Examiner-Gary L. Smith [57] ABSTRACT A safety razor having a head portion including blade positioning structure arranged to permit the blade cutting edge to move relative to the head portion and including biasing means for urging the blade towards a first position of normal exposure and a guard member mounted for movement between first and second positions. The guard member is disposed to engage the blade positioning structure so that movement of the guard member causes movement of the blade cutting edge.

18 Claims, 7 Drawing Figures PATEMEWRWS v 3.871.077 SHEET 3 [If 7 Pmimmmmems 3 8 saw 5 0f 7 PATENTEUMR 1 8l975 SHEET 8 OF 7 RAZOR WITH MOVABLE GUARD AND CONCURRENTLY MOVABLE BLADE PLATFORM This invention relates to safety razors and more particularly to arrangements for enhancing the shaving performance of safety razors.

During a typical shaving operation, a range of conditions are encountered by the cutting edge of the razor blade. A change in conditions may be due to a change in the pressure of the blade edge and razor against the face, as exerted by the user, for example, or contact by the blade edge with an unusual obstruction on the face, such as an especially dense patch of beard hair, or a change in contour of the surface being shaved. It is an object of this invention to provide a novel and improved safety razor that has a dynamic response to conditions encountered during shaving.

A further object is to provide a safety razor which automatically adjusts its shaving geometry during a shaving operation to provide increased comfort and safety of the shaving operation.

The invention provides in a safety razor the feature of automatic adjustment of shaving geometry when a change in conditions is encountered during a shaving operation. More particularly, in one aspect of the invention, a safety razor is provided which has a head portion including structure for positioning a razor blade in shaving position. The blade positioning structure is arranged to permit the blade cutting edge to move relative to the head portion. Biasing means are provided for urging the blade towards a position of normal exposure. A guard member is mounted on the head portion for movement between first and second positions and is disposed to engage the blade positioning structure, whereby movement of the guard member causes movementof the blade cutting edge. Preferably, the guard member also includes first guard structure forward ofand below the cutting edge and second guard structure to the rear of and above the cutting edge, the first guard structure including asurface which so engages the blade positioning structure when the blade is in the position of normal exposure. It is also preferred that the blade positioning structure comprise a support unit including a surface for receiving a razor blade thereupon and structure generally perpendicular to that surface, the biasing means engaging this latter structure. I

In accordance with another feature, thereis provided a safety razor arrangement in which guard structure is movable relative to blade support structure to change the blade tangent angle of the shaving geometry and concurrently moving the blade support structure to maintain substantiallyconstant cutting edge exposure.

The relationships of components of a shaving system are conveniently discussed in terms of certain parameters defined as follows. The blade tangent angle (BTA) of a cutting edge is the angle between the plane bisecting the two planes or facets of the blade that define the edge and the plane through the edge and tangent to the skin engaging surface (e.g., a guard surface) next forward of the edge-The exposure (E) of an edge is the distance of theedge from a plane tangent to both the next forward and the next rearward skin engaging surfaces. The exposure may be positive or negative and is reckoned positive when the edge lies on the skinward side of the doubly tangent plane.

In a preferred embodiment, the guard structure is mounted for rotational movement although other motions such as a linear guard structure motion witha camming engagement of the blade support structure may also be utilized to achieve this desired cooperation. Y

In accordance with another feature of the invention a safety razor has body structure with a first internal bearing portion and a second internal bearing portion positioned below and to the rear of the first internal bearing portion, blade support structure disposed inthe body structure including a surface adapted to support a blade and being movable as a unit relative to the body structure, the unit including a first bearing surface for engagement with said first bearing portion, and a second bearing surface positioned beneath and to the rear of the first bearing surface, for engagement with the second bearing portion, biasing means in engagement with the body structure and exerting an upward force on the support structure and tending to urge the first bearing surface to slide forwardly across the first bearing portion, and stop structure for limiting the forward move-' ment of the blade support structure under the influence of the biasing means and positioning the cutting edge of a blade supported on the blade support structure in predetermined position relative to the body structure.

In one particularly preferred embodiment, the inven tion features a safety razor comprising a generally hollow body member including first and second upper in-' ternal bearing portions and a lower internal bearing portion, the upper bearing portions'engaging the blade. Blade positioning structure is provided and arranged to permit the blade cutting edge to move relative to the body member. That structure comprises a blade support unit including a surface for receiving a blade thereupon and elongated structure below that surface having a bearing surface remote from said blade receiving surface and engaging said lower internal bearing portion of the body member; a spring clamp including a first portion which overlies the blade receiving .surface and a second portion which engages the elongated structure of the support unit, stress within the clamp operative to exert a clamping force (exerted by thefirst portion) upon a blade disposed upon the blade receiving surface; and spring means disposed to exert upon the clamp second portion a force generally in the direction of the blade receiving surface of thesupport unit, the spring means and the body member bearing portions cooperating to'urge the blade receiving surface to forward position in which a blade received thereupon has a normal exposure. Also included is a guard member mounted adjacent the blade cutting edge for movement between first and second positions and disposed H0. 2 is an exploded view of the head portion of the razor of FIG. 1;

FIGS. 3-5 are sectional views of the head portion of the razor of FIG. 1 illustrating a change in shaving geometry during a shaving operation; and

FIGS. 6 and 7 are sectional views analogous to FIGS. 35 illustrating the positioning of a used blade within the razor preparatory to its removal for replacement by a fresh blade.

DESCRIPTION OF PARTICULAR EMBODIMENT The razor of FIG. 1 includes a grip portion 10 and a head portion 12, the main body of the grip portion 10 and the outer body 11 of head portion 12 being molded as a single piece of plastic.

The handle is generally hollow and has integral reinforcing ribs 14 extending between handle side panels 13 and back panel 15. A removable metal cover plate 16 for the open side of the hollow handle 10 is shown in FIG. 1 in a removed position. The cover 16 has an offset upstanding tab 18 at its lower end which is adapted to fit into slot 20 provided in integral wedge 21 at the lower end of handle 10. It also has a pair of notches 22 (only one being visible in FIG. 1) in the lateral edges of walls 23 which fit over a pair of lugs 24 (only one being visible in FIG. 1.) provided on an inner surface 38 of the plastic body 11 of the head portion. Upper portion 25 of plate 16 serves to enclose head portion 12 of the razor.

The head portion 12 includes a guard member 26 pivotally mounted in a position that permits the cutting edge of a razor blade 28 to be disposed within a slot provided in guide member 26 (all as further described below).

The exploded view of FIG. 2 illustrates in greater detail the head portion of the razor and the interrelation of its various components. The blade 28 is retained on support unit 112 by spring clamp member 114, the upper portion 142 of which overlies the blade. The subunit comprising blade 28, support unit 112, and clamp 114 is retained within the body 11 of head portion 12 by retainer member 86. Guard member 26 is mounted for limited rotation upon projections 104 of retainer member 86 such that the cutting edge 108 of the blade 28 is exposed within slot 78 of the guard member. Guard member 26 and retainer member 86 may also be considered as a subunit to simplify certain aspects of the description.

The details of the construction of the outer body 11 of head portion 12 are shown in FIG. 2. Body 11 has a back wall 30, side walls 32, 34 and top wall 36, all molded from high impact plastic and integral with handle portion 10. The volume defined by walls 30, 32, 34, and 36 is enclosed at the lateral portions of the lower side of shaving head 12 by panels 38 each of which merges in a smooth curve at its opposite ends with a side wall (32 or 34) and a side panel 13 of handle 10, respectively. Lugs 24 are integral with walls 38 downwardly and integral with a side wall 32, 34 outwardly.

Top wall 36 merges in a smooth curve (as indicated at 40) with back wall and has generally planar portion 42 and a downwardly sloping portion 44 forward of portion 42. Sloping portion 44 has a recess 46 in its central region and projections 48 of reduced crosssection area protruding from side regions 50. Projections 48 include lower front edges 49 which acts as bearing edges to position the blade 28 and influence its motion. as described below.

Side wall 32 is provided with a forward-opening, elongated, tapered recess 52 in its upper portion. The lower portion 33 of wall 32 has a reduced width from that of the wall portion in the vicinity of recess 52. This width is equal to the width of wall 38. A generally rectangular, forward-facing projection 54 is provided intermediate notch 52 and the lower portion 34 of wall 32. Projection 54 has an arcuate recess 56 at its upper forward corner.

Side wall 34 also has a notch 52 (not visible in FIG. 2) in its upper portion, a reduced width lower portion 33, and a projection 54 having an arcuate recess 56. In addition, it has a notch 57 in the reduced width lower portion 33 immediately below projection 54. The notch 57 permits the insertion of an injector-type blade changer, as described below.

Reinforcing ribs 58 project inwardly from back wall 30 and are integral therewith. Each rib 58 is generally aligned with one of the side panels 13 of handle portion 10. Stops 59 project inwardly from back wall between ribs 58. Additional reinforcing ribs 58a are provided between ribs 58 and walls 32 and 34 respectively (only one rib 58a being visible in FIG. 2).

Support shelves 60 are integral with both back wall 30 and one of said walls 32, 34. Angled lugs 62, of shorter length than shelves 60, are also integral with back wall 30 and a side wall 32, 34 and include a vertical leg 64 integral with shelf 60 and a horizontal leg 66 projecting inwardly from leg 64 over shelf 60.

Structure integral with back wall 30 is provided which includes edges and 67. Edge 65 lies in the plane of the back edge (not visible) of notch 57 and edge 67 lies in the plane of front edge 69 of the reduced width lower portion of wall 34.

Back wall 30 is itself recessed in its lower central portion to provide a surface 68 which is an extension of back panel 15 of handle portion 10. Stud 70 projects from surface 68 and has a V-shaped notch 72 in its outer surface.

Guard member 26 includes upper and lower guard structures 74 and 76, respectively, which are uniformly separated throughout the major portion of their length to provide a slot 78 therebetwee'n. Slot 78 flares at each end of guard member 26 where guard structures 74 and 76 are integral with connecting webs 79. End walls 80 have elongated apertures 82 therein which slope downwardly to the rear at angle to the horizontal of about 14. Guard structure 76 is sharply curved to provide.

rearwardly facing surface 84.

Blade 28 has a back edge 106 and a sharpened front cutting edge 108. An elongated hole 110, itself having a back edge 111, is provided in the central portion of the body of blade 28 closer to edge 106 than edge 108.

Blade positioning structure is provided and comprises support unit 112 and spring clamp member 114. The blade support unit 112 includes planar portion 116 having a width approximately equal to that of blade 28 and a depth somewhat less than that of blade 28. Depending wall 118 is integral with, and generally perpendicular to, portion 116 and includes a downwardly projecting portion 120 having a finger 122 extending still further downwardly and curved somewhat rearwardly. Finger 122 has a smoothly curved surface 124 on the backside of its lower extremity. Depending wall 118 also includes integral arm 126 which projects forward beneath left opening 128 in portion 116 and which serves as a stop for a blade injector, as described below.

Cam structure 130 extends laterally along wall 118 from approximately the center of wall 1 18 to a location under right opening 129. Upward projections 132 of wall 118 bend over openings 128, 129 and are integral with blade overlap structures 134 which overlie openings 128, 129 and which are generally parallel to portion 116. Downwardly offset projections 136 having front surfaces 137 protrude from the front edge 138 of portion 116 near the lateral extremities thereof.

Spring clamp 114 includes inwardly curved back portion 140, top portion 142, bottom portion 144, and arms 146 which project forwardly from the side edges of back portion 140. Top portion 142 includes flared lateral areas 148 and a depressed front portion 150. Bottom portion 144 has a centrally located opening 152 and back portion 140 has a tab portion 154 projecting downwardly below the level of bottom portion 144. Arms 146 include upwardly facing curved surfaces 156 provided by outwardly bent over upward projections 158.

Biasing means 160 comprise a wire spring having upwardly turned ends 162, sloped arms 164, and depressed central portion 166.

The blade positioning structure is held in place in the body 11 of head portion 12 by retainer member 86 which has generally flat, elongated portion 88 having a front edge 90 and is downwardly curved in the back portion of its central region to provide downwardly facing back edge 92. Projections 94 extend rearwardly from the extremity of elongated portion 88 and are generally in the plane of the portion 88. Each projection 94 widens in its rearmost portion. Furthermore, each projection 94 includes a centrally located raised surface 96 which assures a snug fit of projections 94 in the appropriate structure of plastic body 11, as further described below. Guard member supports 98 are provided at the ends of retainer member 86. Each support 98 includes a rear portion 100 aligned with portion 88 and a generally oval forward projecting portion 102 having a centrally located, generally oval, 0.082 inch long projection 104 projecting 0.020 inch outwardly from the outer surface thereof. Projection 104 tapers from a width of about 0.040 inch at its forward portion to a width of about 0.0284 inch at its rear portion. The upper surface of projection 104 slopes downwardly rearwardly at an angle of 16 from the horizontal and the lower surface slopes similarly at an angle of 2. The combination of sloping upper and lower surfaces achieves the taper of the projection 104.

The interrelationship of the various components of the assembled head portion 12 may now be described. Blade 28, support unit 112, and clamp member 114 may be considered as a single sub-assembly. Blade 28 rests upon portion 116 of support 112 with rear edge 106 abutting upward projections 132 of wall 118 of the support unit. With finger 122 inserted through opening 152 of the clamp member 114, top portion 142 of clamp member 114 projects over blade 28 and portion 116 between structures 132 with depressed front portion 150 engaging edge portion 111 in opening 110 of blade 28. Clamp member 114 is made from a resilient metal and is sized such that the inwardly curved back portion 140 will be flexed from its relaxed configuration and top portion 142 will be biased toward portion 116 of support 112 when the clamp member 114 is assembled with the blade 28 and support unit 112 as just described. This assures that the blade 28 will be firmly clamped between clamp 114 and support unit 112 and back edge 106 of blade 28 will be biased firmly against projections 132 of support unit 112.

The sub-assembly just described is inserted into the plastic body 13 with the rear portions of support unit 112 being disposed between the top surface of lugs 62 and the underside of top wall 36, rounded surface 124 on finger 122 of the support unit being disposed in notch 72 of stud 70, and clamp member 114 aligned between ribs 58. The sub-assembly of guard member 26 and retainer member 86 is arranged so that lateral projections 104 on retainer member 86 engage openings 82 in the end walls of guard member 26. The retainer member 86 with guard member 26 attached is inserted with projections 94 being disposed in the space between shelves 60 and lugs 62, raised portions 96 assuring firm frictional retention of member 86 within the plastic body 13. In this position guard member 26 prevents the sub-assembly of blade member 28 and support unit 112 described above from being withdrawn from the body 13 since, as the sub-assembly slides to an extreme forward position, front surfaces 137 of support unit 112 strike the surface 84 of guard member 26.

Spring is disposed with the undersides of upturned ends 162 bearing upon walls 38 and depressed central portion 166 engaging the lower side of bottom wall 144 of clamp member 114 in front of downward projection 154 of back wall 140.

The operation of the blade positioning and biasing system may be described with reference to FIG. 3. The spring means 160 performs a dual function. Its upward component of force (as viewed in FIG. 3) presses the blade 28 in the sub-unit composed of the blade 28, the blade support unit 112, and the clamp member 114 against the lower forward edges 49 (see FIG. 2) of projections 48 of the upper portion 36 of the plastic body 11, thereby eliminating undesirable blade flutter during a shaving operation. The spring 160 also cooperates with the various limitations on movement which the remainder of the razor imposes upon the aforementioned sub-unit, and, in particular, the limitations of the blade bearing on edge 49 just mentioned and the limitation of the notch 72 bearing upon the smoothly curved surface 124 of support unit 112, provide for a counter clockwise biasing of that sub-unit. This biasing, therefore, tends to urge the cutting edge 108 of blade 28 forward (left in FIG. 3) to a normal" position in which projections 136 of support unit 112 are in contact with surface 84 of guard member 26.

FIGS. 3-5 are transverse sectional views of the head portion of the razor described above taken along a reference line through the assembled head portion, which reference line would intersect support unit 112 along reference line X in FIG. 2. These FIGS. illustrate the action of the razor mechanism which occurs within the head portion as the guard member rotates upon encountering changing shaving conditions.

In FIG. 3 the blade 28 is in its forwardmost position and the guard member 26 is rotated in its fully up (clockwise in FIGS. 3-5) position. With the blade 28 and guard member 26 in those positions the exposure of the blade shaving edge 108 beyond a tangent reference line Y (drawn between the structure above and below the blade) is a predetermined value (e.g., a small positive value).

In FIG. 4 the guard member 26 has rotated downwardly (i.e., counterclockwise) and in so doing causes a retraction of the blade due to the force exerted by surface 84 of the guard member on projection 136 of the blade support unit. The amount of rotation shown in FIG. 4 is approximately one-half the total rotation of which guard member 26 is capable. This is indicated by the fact that the back, tapered end of projection 104 is centered within the wider back portion of opening 82.

In FIG. 5 the guard member 26 has rotated to its extreme downward or clockwise position with the lower surface of projection 104 engaging the lower surface of opening 82 thereby providing a stop to prevent further rotation. The blade support unit has been caused to retract even further against the biasing force of spring 160.

The retraction rate of the blade caused by dynamic movement of the guard member is regulated to maintain a relatively constant exposure. Since the rotational center of the guard member does not coincide with the blade edge, the tangent line Y will swing on an arc exposing more and more of the blade edge as the guard member rotates clockwise. The point of contact between projection 136 and surface 84 is in a predetermined spatial relationship with the center of rotation of the guard causing the blade edge to retreat as the tangent line Y rotates and thus maintaining the desired exposure. Exposure is reduced when the blade retracts in response to high cutting forces during shaving.

The position of notches 22 with respect to upper portion 25 of cover plate 16 is chosen such that when notches 22 are engaged with lugs 24, inner surface 27 of portion 25 is biased against edge 90 of retainer 86 to securely hold the entire assembly of retainer 86, guard 26, support unit 112, blade 28, and clamp 114 within the head portion 12. The upper portion 25 is spaced apart from front edge 69 of the lower portion of wall 34. The gap between edge 69 and portion 25 of the cover plate 16 cooperates with notch 57 to produce an inverted L-shaped opening in the right side (as viewed in FIGS. 1 or 2) of the assembled razor. This opening is suitable for insertion of an arm portion of an injector type razor blade dispenser. Edges 65 and 67 serve as guides for the camming portion of such a dispenser inserted into the razor head. Cam 130 is positioned to be engaged by the portion of the inserted dispenser key into the razor so as to retract blade platform subassembly moving edge 108 rearwardly from between guard structures 74 and 76. Surfaces 156 are also engaged by the blade dispenser portion so as to lower the support unit 112 with lateral projections 139 resting on the sloping surfaces 99 of the retainer 86 thereby bringing the blade into alignment with notches 52 to permit removal of the used blade from support unit 112 and clamp member 114 and insertion of a fresh blade through notch 52 in wall 34. Projection 126 on support unit 112 serves as a stop to properly position the inserted key portion of the blade dispenser.

FIGS. 6 and 7 illustrate how the razor mechanism acts to position the blade 28 so as to be free from interference from guard member 26 and to be positioned to be aligned with notches 52 upon insertion of an arm or key portion 200 of an injector-type razor blade dispenser. FIG. 6 illustrates the arm 200 partially inserted into the razor, and FIG. 7 illustrates the arm fully inserted into the razor (i.e., with its remote end abutting stop 126 on blade support unit 112).

The arm 200 has the general cross-sectional form of an inverted L. The long vertical side 202 of the L and the long horizontal side 204, after the arm 200 is fully inserted (see FIG. 7) abut the inner surface of upper portion 25 of plate 16 and surface 92 of retainer member 86, respectfully. The locations of arm 200 surfaces 206 and 208 with respect to surfaces 202 and 204 are chosen such that upon full insertion (as in FIG. 7) with surface 206 in contact with the front surface of cam member and surface 208 in contact with surfaces 156 on clamp member 114, the sub-unit consisting of blade 28, blade support 112, and clamp 114 will be so positioned that the blade 28 is aligned with notches 52 and its tip 108 is retracted from the slot 78 of guard member 26.

As can be seen from a comparison of FlGS. 6 and 7, the insertion of arm 200 causes rearward and downward movement of the above-mentioned sub-unit in response, respectfully, to the force exerted on cam 130 by surface 206 and upon surfaces 156 by surface 208. This motion produces a stressing of the spring means 160 as is evident from the greater deformation of spring means 160 in FIG. 7 than in FIG. 6. Furthermore, the internal surfaces of the plastic body 11 of head portion 12 of the razor are shaped such that when the clamp 114 contacts that inner surface at the junction 210, clamp portion 142 is forced forward relative to platform 116 thereby relieving the rearward biasing force exerted on the blade 28.

With the blade 28 thus aligned with notches 52 and spaced from guard member 26, replacement of a used blade 28 with a fresh blade may be accomplished in conventional injector manner.

As the used blade 28 is forced out through notch 52 by the new blade, the new blade slides between lower surface of top portion 142 of spring clamp 114 and surface 116 of support 112. The residual downward clamping force exerted by top portion 142 prevents the new blade from sliding beyond its proper position in alignment between end walls 80 of guard 26.

When the arm 200 is withdrawn, spring 160 moves the support unit 112 upward and forward sliding on bearing surfaces 49 and 72. As the support unit 112 moves forward, the clamp 114 is released from contact with the head portion inner surface and latch portion of clamp 114 engages edge portion 111 of blade 28 and biases the rear edge 106 against reference surfaces 132 of support 112. The edge 108 of the blade is properly located with reference to the surfaces 137 of the support unit 112 and platform subunit surfaces 137 engage guard surfaces 84 to rotate the guard unit to its initial position of minimum BTA for control of exposure beyond tangent Y.

Other embodiments will occur to those skilled in the art and are within the following claims.

We claim:

1. A safety razor having a head portion including blade positioning structure, said blade positioning structure being arranged to permit the blade cutting edge to move relative to said head portion and including biasing means for urging the blade towards a first position of normal exposure, and a guard member mounted for movement between first and second positions to change the blade tangent angle of the shaving geometry, said guard member disposed to engage said blade positioning structure, movement of said guard member causing concurrent movement of said blade cutting edge relative to said guard member and to said head portion and against the force of said biasing means to maintain substantially constant cutting edge ture in predetermined position relative to said body exposure. structure.

2. A safety razor for use with a blade comprising 4. A safety razor comprising body structure having a a generally hollow body member including first and first internal bearing portion and a second internal second upper internal bearing portions and a lower 5 bearing portion positioned below and to the rear of said internal bearing portion, said upper bearing porfirst internal bearing P tions for slidingly e gagin th bl d blade support structure disposed in said body strucblade positioning structure arranged to permit the ture including a Surface adapted to support a blade blade cutting edge to move relative to said body member and comprising a blade support unit including a blade receiving surface for receiving a blade thereupon and elongated and being movable as a unit relative to said body structure, said support structure including a first bearing surface for engagement with said first bearing portion, and a second bearing surface positioned beneath and to the rear of said first bearing surface for engagement with said second bearing portion, said support structure normally being in engagement with said first and second bearing portions and spaced from other portions of said body structure below said blade receiving surface having a bearing surface remote from said blade receiving surface and slidingly engaging said lower internal bearing portion of said body member,

a spring clamp including a first portion which overlies said blade receiving surface and second and third Y portions which engage said elongated structure of blasmg means engagement with Said P Struc' ture and exerting an upward force on said support said blade support unit, stress within said clamp produced by the engagement of said second and third portions with said elongated structure operative to exert a clamping force by said first portion upon a blade disposed upon said blade receiving surface, and

spring means disposed in engagement with said spring clamp and exerting a force generally in the direction of said blade receiving surface of said support unit, to slide said blade positioning struc 3O ture along said body member bearing portions to urge said blade receiving surface to a forward position in which a blade received thereupon has a normal exposure; and

a guard member mounted adjacent the blade cutting edge for movement between first and second positions anddisposed to engage said blade support unit, whereby movement of said guard member causes sliding movement of said blade support unit along said body member bearing portions against the influence of said spring means.

3. A safety razor comprising body structure having a first internal bearing portion and a second internal bearing portion positioned below and to the rear of said first internal bearing portion, 4

blade support structure disposed in said body strucstructure, said biasing means tending to urge said first bearing surface to slide forwardly across said first bearing portion, and

stop structure for limiting the forward movement of said blade support structure under the influence of said biasing means and positioning the cutting edge of a blade supported on said blade support structure in predetermined position relative to said body structure, said stop structure being movable relative to said body structure and including a guard member, said guard member being movable relative to said blade support structure to change the blade tangent angle of the shaving geometry of the shaving system and concurrently moving said blade support structure to maintain substantially constant cutting edge exposure.

5. The razor as claimed in claim 4 wherein said stop structure is mounted for rotational movement.

6. The razor as claimed in claim 4 wherein said stop structure includes guard surfaces forward and rearward of said predetermined edge position.

7. A safety razor comprising body structure having a first internal bearing portion and a second internal bearing portion positioned below and to the rear of said first internal bearing portion,

blade support structure disposed in said body struc- LII ture including a' surface adapted to support a blade and being movable as a unit relative to said body structure, said support structure including a first exerting an upward force on said support structure, said biasing means tending to urge said first bearing surface to slide forwardly across said first bearing portion, and

stop structure for limiting the forward movement of said blade support structure under the influence of said biasing means and positioning the cutting edge of a blade supported on said blade support structure and being movable asa unit relative to said body structure, said support structure including a surface adapted to support a blade, a reference surbearing surface for engagement with said first bearface a Spring member f i i a blade iing P and a Second bearing surface P tioned on said support surface to urge an edge of tioned beneath and t0 the rear Of said first bearing aid blade into engagement with aid reference sur- Surface tot engagement with Said Second beating face, a first bearing surface for engagement with Portion, Said pp Structure normally being in said first bearing portion, and a second bearing surengagement with said first and Second beating P face positioned beneath and to the rear of said first tions and spaced from other portions Of said body bearing surface for engagement with said second structure, bearing portion, said support structure normally biasing means separate from said blade support strucbeing in engagement with aid first and second ture in engagement with Said body Structu e and bearing portions and spaced from other portions of said body structure,

biasing means in engagement with said body structure and exerting an upward force on said support structure, said biasing means tending to urge said first bearing surface to slide forwardly across said first bearing portion, and

stop structure for limiting the forward movement of said blade support structure under the influence of 1 1 said biasing means and positioning the cutting edge of a blade supported on said blade support structure in predetermined position relative to said body structure.

8. A safety razor comprising body structure having a first internal bearing portion, a second internal bearing portion positioned below and to the rear of said first internal bearing portion, and an aperture for receiving a dispenser key,

blade support structure disposed in said body structure including a surface adapted to support a blade and being movable as a unit relative to said body structure, said support structure including :1 reference surface, a spring member for biasing a blade positioned on said support surface to urge an edge of said blade into engagement with said reference surface, said spring member having a projecting portion extending rearwardly of said blade support structure and spaced from a surface of said body structure, a first bearing surface for engagement with said first bearing portion, a second bearing surface positioned beneath and to the rear of said first bearing surface for engagement with said second bearing portion,- said support structure normally being in engagement with said first and second bearing portions and spaced from other portions of said body structure, a cam surface engageable with said injector key, said cam surface as engaged by said dispenser key tending to force said blade support structure rearwardly to cause said projecting portion to engage said body structure and reduce the clamping force exerted by said spring member on said blade,

biasing means in engagement with said body structure and exerting an upward force on said support structure, said biasing means tending to urge said first bearing surface to slide forwardly across said first bearing portion, and

stop structure for limiting the forward movement of said blade support structure under the influence of said biasing means and positioning the cutting edge of a blade supported on said blade support structure in predetermined position relative to said body structure. a

9. The razor as claimed in claim 8 wherein said biasing means is in engagement with said. spring member.

10. A safety razor comprising body structure,

blade support structure disposed in said body structure including a surface adapted to support a blade and being movable as a unit relative to said body structure,

biasing means in engagement with said body structure and exerting a force on said support structure, and

guard structure, said guard structure being movable relative to said blade support structure to change the blade tangent angle of the shaving geometry and concurrently moving said blade support structure against the force of said biasing means to maintain substantially constant cutting edge exposure.

11. The razor as claimed in claim 10 wherein said guard structure is mounted for rotational movement to provide a range of blade tangent angles.

12. The razor as claimed in claim 10 wherein said guard structure includes a first guard surface forward of said predetermined edge position and a second guard surface rearward of said predetermined edge position, said guard surfaces defining said cutting edge exposure.

13. The razor as claimed in claim 10 wherein said body structure includes an aperture for receiving a dispenser key and said blade support structure includes a cam surface engageable with said injector key for moving blade support structure relative to said body structure to release a blade positioned on said support surface.

14. The razor as claimed in claim 10 wherein said blade support structure is mounted in said body structure to move away from said guard structure in response to resistance encountered in shaving to reduce the exposure of the blade edge, thereby increasing the safety and comfort of the shaving operation.

15. A safety razor comprising body structure,

blade support structure disposed in said body structure including a surface adapted to supprot a blade and a reference surface and being movable as a unit relative to said body structure, a spring member for biasing a blade positioned on said support surface to urge the rear edge of said blade into engagement with said reference surface,

biasing means in engagement with said body structure and exerting a force on said support structure, and

guard structure, said guard structure being movable relative to said blade support structure to change the blade tangent angle of the shaving geometry and concurrently moving said blade support structure against the force of said biasing means to maintain substantially constant cutting edge exposure.

16. A safety razor comprising body structure having a first internal bearing portion and a second internal bearing portion positioned below and to the rear of said first internal bearing portion,

blade support structure disposed in said body structure including a surface adapted to support a blade and being movable as a unit relative to said body structure, said support structure including a first bearing surface for sliding engagement with said first bearing portion, and a second bearing surface positioned beneath and to the rear of said first bearing surface for sliding engagement with said second bearing portion,

biasing means in engagement with said body structure and exerting an upward force on said support structure, said biasing means tending to urge said first bearing surface to slide forwardly across said first bearing portion, and

guard structure including a guard surface positioned structure being mounted in said body structure to i move away from said guard surface in response to blade positioned on said support surface to urge the rear edge of said blade into engagement with said reference surface, and said body structure includes an aperture for receiving a dispenser key and said blade support structure includes a cam surface engageable with said injector key for moving blade support structure relative to said body structure to release the clamping force exerted by said spring member on a blade positioned on said support surface. 

1. A safety razor having a head portion including blade positioning structure, said blade positioning structure being arranged to permit the blade cuttIng edge to move relative to said head portion and including biasing means for urging the blade towards a first position of normal exposure, and a guard member mounted for movement between first and second positions to change the blade tangent angle of the shaving geometry, said guard member disposed to engage said blade positioning structure, movement of said guard member causing concurrent movement of said blade cutting edge relative to said guard member and to said head portion and against the force of said biasing means to maintain substantially constant cutting edge exposure.
 2. A safety razor for use with a blade comprising a generally hollow body member including first and second upper internal bearing portions and a lower internal bearing portion, said upper bearing portions for slidingly engaging the blade; blade positioning structure arranged to permit the blade cutting edge to move relative to said body member and comprising a blade support unit including a blade receiving surface for receiving a blade thereupon and elongated structure below said blade receiving surface having a bearing surface remote from said blade receiving surface and slidingly engaging said lower internal bearing portion of said body member, a spring clamp including a first portion which overlies said blade receiving surface and second and third portions which engage said elongated structure of said blade support unit, stress within said clamp produced by the engagement of said second and third portions with said elongated structure operative to exert a clamping force by said first portion upon a blade disposed upon said blade receiving surface, and spring means disposed in engagement with said spring clamp and exerting a force generally in the direction of said blade receiving surface of said support unit, to slide said blade positioning structure along said body member bearing portions to urge said blade receiving surface to a forward position in which a blade received thereupon has a normal exposure; and a guard member mounted adjacent the blade cutting edge for movement between first and second positions and disposed to engage said blade support unit, whereby movement of said guard member causes sliding movement of said blade support unit along said body member bearing portions against the influence of said spring means.
 3. A safety razor comprising body structure having a first internal bearing portion and a second internal bearing portion positioned below and to the rear of said first internal bearing portion, blade support structure disposed in said body structure including a surface adapted to support a blade and being movable as a unit relative to said body structure, said support structure including a first bearing surface for engagement with said first bearing portion, and a second bearing surface positioned beneath and to the rear of said first bearing surface for engagement with said second bearing portion, said support structure normally being in engagement with said first and second bearing portions and spaced from other portions of said body structure, biasing means separate from said blade support structure in engagement with said body structure and exerting an upward force on said support structure, said biasing means tending to urge said first bearing surface to slide forwardly across said first bearing portion, and stop structure for limiting the forward movement of said blade support structure under the influence of said biasing means and positioning the cutting edge of a blade supported on said blade support structure in predetermined position relative to said body structure.
 4. A safety razor comprising body structure having a first internal bearing portion and a second internal bearing portion positioned below and to the rear of said first internal bearing portion, blade support structure disposed in said body structure including a surface adapted to support a blade and being movable as a unit relative tO said body structure, said support structure including a first bearing surface for engagement with said first bearing portion, and a second bearing surface positioned beneath and to the rear of said first bearing surface for engagement with said second bearing portion, said support structure normally being in engagement with said first and second bearing portions and spaced from other portions of said body structure, biasing means in engagement with said body structure and exerting an upward force on said support structure, said biasing means tending to urge said first bearing surface to slide forwardly across said first bearing portion, and stop structure for limiting the forward movement of said blade support structure under the influence of said biasing means and positioning the cutting edge of a blade supported on said blade support structure in predetermined position relative to said body structure, said stop structure being movable relative to said body structure and including a guard member, said guard member being movable relative to said blade support structure to change the blade tangent angle of the shaving geometry of the shaving system and concurrently moving said blade support structure to maintain substantially constant cutting edge exposure.
 5. The razor as claimed in claim 4 wherein said stop structure is mounted for rotational movement.
 6. The razor as claimed in claim 4 wherein said stop structure includes guard surfaces forward and rearward of said predetermined edge position.
 7. A safety razor comprising body structure having a first internal bearing portion and a second internal bearing portion positioned below and to the rear of said first internal bearing portion, blade support structure disposed in said body structure and being movable as a unit relative to said body structure, said support structure including a surface adapted to support a blade, a reference surface, a spring member for biasing a blade positioned on said support surface to urge an edge of said blade into engagement with said reference surface, a first bearing surface for engagement with said first bearing portion, and a second bearing surface positioned beneath and to the rear of said first bearing surface for engagement with said second bearing portion, said support structure normally being in engagement with said first and second bearing portions and spaced from other portions of said body structure, biasing means in engagement with said body structure and exerting an upward force on said support structure, said biasing means tending to urge said first bearing surface to slide forwardly across said first bearing portion, and stop structure for limiting the forward movement of said blade support structure under the influence of said biasing means and positioning the cutting edge of a blade supported on said blade support structure in predetermined position relative to said body structure.
 8. A safety razor comprising body structure having a first internal bearing portion, a second internal bearing portion positioned below and to the rear of said first internal bearing portion, and an aperture for receiving a dispenser key, blade support structure disposed in said body structure including a surface adapted to support a blade and being movable as a unit relative to said body structure, said support structure including a reference surface, a spring member for biasing a blade positioned on said support surface to urge an edge of said blade into engagement with said reference surface, said spring member having a projecting portion extending rearwardly of said blade support structure and spaced from a surface of said body structure, a first bearing surface for engagement with said first bearing portion, a second bearing surface positioned beneath and to the rear of said first bearing surface for engagement with said second bearing portion, said support structure normally being in engagement with said first and second bearing portions and spaced From other portions of said body structure, a cam surface engageable with said injector key, said cam surface as engaged by said dispenser key tending to force said blade support structure rearwardly to cause said projecting portion to engage said body structure and reduce the clamping force exerted by said spring member on said blade, biasing means in engagement with said body structure and exerting an upward force on said support structure, said biasing means tending to urge said first bearing surface to slide forwardly across said first bearing portion, and stop structure for limiting the forward movement of said blade support structure under the influence of said biasing means and positioning the cutting edge of a blade supported on said blade support structure in predetermined position relative to said body structure.
 9. The razor as claimed in claim 8 wherein said biasing means is in engagement with said spring member.
 10. A safety razor comprising body structure, blade support structure disposed in said body structure including a surface adapted to support a blade and being movable as a unit relative to said body structure, biasing means in engagement with said body structure and exerting a force on said support structure, and guard structure, said guard structure being movable relative to said blade support structure to change the blade tangent angle of the shaving geometry and concurrently moving said blade support structure against the force of said biasing means to maintain substantially constant cutting edge exposure.
 11. The razor as claimed in claim 10 wherein said guard structure is mounted for rotational movement to provide a range of blade tangent angles.
 12. The razor as claimed in claim 10 wherein said guard structure includes a first guard surface forward of said predetermined edge position and a second guard surface rearward of said predetermined edge position, said guard surfaces defining said cutting edge exposure.
 13. The razor as claimed in claim 10 wherein said body structure includes an aperture for receiving a dispenser key and said blade support structure includes a cam surface engageable with said injector key for moving blade support structure relative to said body structure to release a blade positioned on said support surface.
 14. The razor as claimed in claim 10 wherein said blade support structure is mounted in said body structure to move away from said guard structure in response to resistance encountered in shaving to reduce the exposure of the blade edge, thereby increasing the safety and comfort of the shaving operation.
 15. A safety razor comprising body structure, blade support structure disposed in said body structure including a surface adapted to supprot a blade and a reference surface and being movable as a unit relative to said body structure, a spring member for biasing a blade positioned on said support surface to urge the rear edge of said blade into engagement with said reference surface, biasing means in engagement with said body structure and exerting a force on said support structure, and guard structure, said guard structure being movable relative to said blade support structure to change the blade tangent angle of the shaving geometry and concurrently moving said blade support structure against the force of said biasing means to maintain substantially constant cutting edge exposure.
 16. A safety razor comprising body structure having a first internal bearing portion and a second internal bearing portion positioned below and to the rear of said first internal bearing portion, blade support structure disposed in said body structure including a surface adapted to support a blade and being movable as a unit relative to said body structure, said support structure including a first bearing surface for sliding engagement with said first bearing portion, and a second bearing surface positioned beneath and to the rear of said first bearing surface For sliding engagement with said second bearing portion, biasing means in engagement with said body structure and exerting an upward force on said support structure, said biasing means tending to urge said first bearing surface to slide forwardly across said first bearing portion, and guard structure including a guard surface positioned forwardly of said blade support surface, and a stop surface for limiting the forward movement of said blade support structure under the influence of said biasing means and positioning the cutting edge of a blade supported on said blade support structure in predetermined position relative to said body structure, said guard surface being movable relative to said blade support structure to change the blade tangent angle of the shaving geometry of the shaving system and concurrently moving said blade support structure to maintain substantially constant cutting edge exposure, and said blade support structure being mounted in said body structure to move away from said guard surface in response to resistance encountered in shaving to reduce the exposure of the blade edge, thereby increasing the safety and comfort of the shaving operation.
 17. The razor as claimed in claim 16 wherein said guard structure is mounted for rotational movement and includes guard surfaces forward and rearward of said predetermined edge position.
 18. The razor as claimed in claim 17 wherein said blade support structure includes a reference surface and further including a spring member for biasing a blade positioned on said support surface to urge the rear edge of said blade into engagement with said reference surface, and said body structure includes an aperture for receiving a dispenser key and said blade support structure includes a cam surface engageable with said injector key for moving blade support structure relative to said body structure to release the clamping force exerted by said spring member on a blade positioned on said support surface. 